This invention relates to a method of detecting when a moving component of an electromagnetically operable device attains a final position after de-energising a winding forming part of the device.
A example of such a device is an electromagnetically operable spill control valve forming part of the fuel system of an internal combustion engine. When the winding is energised the spill control valve member moves to its closed position against the action of a spring. When the winding is de-energised the valve member moves to its open position as determined by a stop, under the action of the spring. For the assessment of the operation of the spill control valve it is useful to have a signal indicative of when the valve member engages the stop.